Sharp-shinned Hawk

About the Sharp-shinned Hawk

The Sharp-shinned Hawk is the smallest of North America's three accipiters, or forest hawks, with a body length of roughly 9 to 13 inches and a wingspan of 17 to 22 inches. Adults show slate blue-gray upperparts, finely rufous-barred underparts, red eyes, and a long, square-tipped tail with a narrow white terminal band. Juveniles are browner above with coarse streaking below. As in most raptors, females run substantially larger than males, sometimes by a quarter or more in mass, which can help separate pairs in the field; this reversed size dimorphism, with females larger than males, is thought to reduce direct competition between the sexes for prey and may let a mated pair exploit a broader range of prey sizes than either sex could alone.

This hawk breeds across dense coniferous and mixed forests of Canada, the northern United States, and higher-elevation woods further south, using closed canopy cover to hunt by ambush. In Oklahoma it functions mainly as a migrant and winter visitor rather than a local breeder, passing through in numbers each fall and spring and settling into wooded areas, thickets, and suburban neighborhoods for the colder months before moving on toward wintering grounds that extend into Central America. Fall migration can be dramatic at watch sites along ridgelines and lakeshores, where hundreds of individuals may stream past on a single good flight day, riding the same winds that carry other migrating raptors south.

Sharp-shinned Hawks hunt almost exclusively small songbirds, using short bursts of speed and tight, agile maneuvering through branches and brush to surprise prey rather than chasing it in open air. Its short, rounded wings and long tail, typical of accipiters generally, are built for exactly this kind of quick, twisting flight through cluttered vegetation rather than for sustained speed in the open. Backyard bird feeders often draw them in winter, not for the seed itself but because feeders concentrate the small birds the hawks prey on; a sudden scattering of sparrows is sometimes the only clue one has passed through. They will also take large flying insects opportunistically, and, like other accipiters, sometimes cache surplus prey temporarily rather than consuming it immediately.

Pairs build a stick nest high in a dense conifer, and the female carries out most of the incubation of a clutch that typically numbers three to eight eggs while the male provisions her with food. Because the sexes differ so much in size, the male typically continues to bring most of the food to the nest even after the young hatch, while the larger female stays close to guard and brood the nestlings, only gradually taking a greater role in hunting as the young grow and need more food than the male alone can reliably supply.

Because the species stays so well hidden within forest cover, much of what is known about its nesting habits comes from banding studies and dedicated nest-watching rather than casual observation. Even experienced birders often struggle to distinguish this species reliably from the very similar, slightly larger Cooper's Hawk, a confusion that persists throughout its range and is compounded by the overlap in size between a large female Sharp-shinned Hawk and a small male Cooper's Hawk, meaning head shape, tail shape, and overall proportions often matter more than size alone when separating the two in the field.

Fall migration counts at established hawk-watch sites provide much of what is known about the species' population trends, since the birds are otherwise so widely dispersed and secretive during the breeding season that direct counts on the nesting grounds are impractical across most of its range. Sharp-shinned Hawks are also known for occasional long-distance irruptive movements in some years, when unusually large numbers push farther south than typical, likely tied to fluctuations in the abundance of the small songbirds that make up their prey base further north.